Rotary cutter.



v H, M. LOOM ER.

ROTARY CUTTER. APPL ICATION FILED MAR-1Bpl9l6- Patented Nov. 20, 1917-.

MFA/727R;

eras earn MACHINERY COMPANY. OF PATERSON',

J ERSEY.

NEW JERSEY, A CORPORATION OF NEW ROTARY CUTTER.

Specification of Letters Patent. pategnted N0 ,'20, 1917,

Application filed March 18, 1916. Serial No. 85,196.

To all whom it may concern:

Be it known that I, HENRY M. LOOMER, a citizen of the United States,residing at Beverly, in the county of Essex and State of Massachusetts,have invented certain Improvements in Rotary Gutters, of which thefollowing description, in connection with the accompanying drawings, isa specification, like reference characters on the drawings indicatinglike parts in the several figures.

This invention relates to rotarycutters such as are used in themanufacture of shoes for trimming the edges of shoe soles. The inventionis herein illustrated in its application to a type of cutter which isparticularly adapted for trimming the shank portion of the sole edge,but it should be understood that this type of cutter is only an exampleof various types included within the field of applicability of theinvention and that this field is not necessarily restricted to cuttersused in shoe manufacture.

The invention provides a cutter of great durability which may beproduced at comparatively small expense, and provides also a novel andimproved method for use in the manufacture of rotary cutters. Thevarious novel features of the cutter and the several steps of theimproved method will be described with reference to the accompanyingdrawings and pointed out'in the claims.

In the drawings I Figures 1 and 2 show a cutter blank in side and endelevations respectively,

Figs. 3 and 4 show the blank in end and side elevations respectively ata stage in the manufacture of the cutter subsequent to that representedby Figs. 1 and 2,

Figs. 5 and 6 cutter, corresponding respectively to Figs. 3 and 4, Fig.(5 illustrating also one of the steps in the manufacture of the cutter,and

Fig. 7 is a developed sectional view on the line 7-7 of Fig. 5.

In the manufacture of the illustrated cutter a blank 2 is first made inthe form shown in Figs. 1 and 2, this blank being circular in outlineand the periphery of the blank having a transverse contour which is thecomplement of the transverse contour desired for the edge of the shoesole. Since the edge of a sole in the shank should usuare views ofthefinished transversely ofthe periphery of the blank.

This slot may be formed conveniently in the usual way by theuse of amilling cutter. In the illustrated construction the slot at extends I insubstantially parallel relation to the axis of the blank, but it may bevariously disposed as, for example, the front face of the cutter toothto form an angle with the aXis.

to cause the plane of I Either before or after the slot 4 is cut in theblank, as may be found most convenient, the blank is bored in suchmanner as to permit the cutter to be mounted upon the end of theoperating shaft. The bore, shown at 8, which as usual enlarges slightlyfrom the smaller to the larger end of the cutter, is somewhat offsetfrom the center of the blank and is nearest to that portion of theperiphery which is diametrically opposite to the cutting edge 6, asshown in Figs'3 and 4:. This affords the requisite radialclearance forthe peripheral'surface of the cutter behind the cutting edge; and in acutter formed in this manner the slow and expensive step of backing offor tipping back the teeth, which is necessary in cutters as usually madehere tofore, is eliminated. In a cutter of the type shown in thedrawings, moreover, in whic the peripheral surface slopes transverselyfrom a smaller as well as radial clearance is necessary'for the bestresults; otherwise that part of the cutting edge indicated at a, forexample, in Fig. at will not cut as freely as the part indicated at b,and the portion of the peripheral surface behind the part a will have arelatively greater tendency to rub the work. According to thisinvention, such lateral clearance is afforded simply by inclining thebore 8 relatively to the axis of the cutter blank about which theperipheral surface is described. This will be evident from reference toFig. in which the axis of the blank is indicated atc and the axis of thebore 8,

to a larger diameter, lateral has is not only below the axis 0 but isalso inclined downwardly relatively to the axis a in the direction ofthe larger end of the cutter. Both radial and lateral clearance for thecutter are thus afforded simply by the manner of locating the bore 8.

It will be apparent, from reference to Fig. 4, that at this stage in themanufacture of the cutter the planes of the end faces of the blank areinclined relatively to the axis cZ ofthe bore 8. It is usually desirablethat the smaller end face of the finished cutter lie in a planeperpendicular to this axis, since in the use of the cutter the usualshield engages this face and the edge of the shield should preferablyrotate in a true plane. Preferably also the larger end face of thecutter should lie similarly in a plane perpendicular to the axis ofrotation. In the cutter herein shown, therefore, both end faces aredressed off to bring them into perpendicular relation to the axis (Z.This step will be more clearly understood from a comparison of theplanes of the end faces of the blank in Fig. 4. with the dash lines 6and 7 which correspond to the planes of the end faces of the finishedcutter seen in Fig. 6.

The steps thus far detailed are all that are necessary to the productionof a satisfactory operative cutter. By reference to Fig. however, itwill be seen that the portion of the peripheral surface indicated at 10,while nearer to the of the bore 8 than the corresponding portionadjacent to the cutting edge 6, is farther from the axis than theportion directly below the bore 8. Since the, cutting edge issubstantially at the portion of the peripheral surface farthest distantfrom the axis, it will be apparent that the extent to which a cuttersuch as shown in Fig. 3 can be ground, while still maintaining clearancewith reference to the part 10, is limited to a point at acircumferential distance from the cutting edge slightly less than thecircumferential width of the slot In order to prolong the usefulness ofthe cutter, therefore, it is preferable to cut away a portion at theperiphery of the blank between the point of least eccentricity and thefront edge of the slot l. This may be done in any convenient way, as bythe use of a common form of b: cking off too] indicated at 12 in Fig. 6.In the cutter herein shown enough of the blank is cut away to cause allportions of the peripheral surface between the two points mentioned tolie at least as near to the axis of rotation as the correspondingportions of the surface at the point of least eccentricity. the cutterbeing turned about the axis (Z while presented for the action of thetool 12. A cutter as thus formed may be ground until the cutting edge isfinally at a point nearly 180 degrees distant from the point at which itis located when the cutter is new.

By reference to Figs. 5, 6 and 7 it will be seen that the finishedcutter herein shown presents an unbroken peripheral surface ex tendingin a curve from the cutting edge 6 to the opposite side of the slot l.From the point 9 at the edge 6 (Fig. 5) to a point a. substantiallydiametrically. opposite, the curve of the peripheral surface of thecutter has a relatively long radius (for example 2', Fig. 5) and isdescribed about an axis (0, Figs. 2- and t) which is nearer to the edge6 than the axis of rotation of the cutter (5], Figs. l and 6) and isnon-parallel to the axis of rotation. The curye of the peripheralsurface, beginning the cutting edge, thus gradually approaches the axisof rotation of the cutter for substantially half the distance around thecutter. From the point it to the point 7' at the front edge of the slotf the peripheral surface has a relatively short radius for example h,Fig. 5) and is described about an axis substantially coincident. withthe axis of rotation of the cutter. That portion of the peripheralsurface from 71 to j is thus substantially within the curve of the pathof revolution of that portion of the periphery at the point of leasteccentricity or, in other words, is at no point farther from the axisthan that point in the same plane of revolution which is opposite to thepoint h, Fig. 5. Y

The illustrated cutter is provided with the usual rand cutting lip 14.It will be apparent that in a cutter made according to the method hereinexplained the inner surface of this lip will be increasingly offsetrelatively to the plane of rotation, for sub.- stantially half thedistance around the cutter, in the same sense the portion of thperiphery of the cutter behind that part of the cutting edge indicatedat a. Suiiicient clearance of the lip, however, is insured by reason ofthe slope on its bined with the eccentricity of the cutter, as a resultof which that small portion of the surface of the lip which might be inposition to rub the work actually recedes from the work behind thecutting edge. clear from reference to Fig. 7 which shows the lip in asection developed from curve the center of which is at the axis ofrotation of the cutter. The line 16 is the line forming the cornerbetween the lip and the face 6, and is seen to be farther from the outerface 6 at 18 than at 20, the latter point being near the cutting edge.The shaded porion of Fig. 7 shows that the radial drop in combinationwith the slope 22 of the side of the lip gives it a clearance.

It will be readily apparent from the preceding description that, withincomparatively wide limits, the shape and size of the recess 4 areimmaterial, as is also the manner in which. this recess is formed toprovide the cutting edge, and that although the This will be peripherybe curved of the cutter may conveniently as shown and described betweenthe points it and j, the portion of thecutter between the point it andthe front ofthe cutter tooth may have other forms consistent With theobject of affording" such clearance as may be desired in order toprolong the usefulness of the cutter. In these respects, as Well asothers, therefore, the invention in its broader aspects is not to beregarded as limited to the precise constructionshown and described, norto'the precise manner herein indicated of carrying out the differentsteps of the improved method. It will be apparent also that themanufacture of the improved cutter is not dependent upon a series ofsteps carried out in the precise order in which they are detailed in theforegoing description, and it'should be understood that except asrequired by the context the claims to the novel method herein disclosedarenot to be regarded as limited to a series of steps in the preciseorder named.

Having described the invention, What I claim as new .and desire tosecure by Letters Patent of the United States is i 1, A rotary cutterformed as a Single piece provided with a bore to permit the cutter to bemounted upon its operating shaft and having a single cutting edgetransverse to'its periphery, the cutter having a peripheral surfaceextending from said cutting edge on a curve that gradually approachesthe axis of said bore for substantially half the distance around thecutter.

2. A rotary cutter formed as a single piece provided with a bore topermit the cutter to be mounted upon its operating shaft and having asingle cutting edge transverse to its periphery, a portion oftheperipheral surface of revolution of the cutter forming a curve beginningat said cutting edge and gradually approaching the axis of said'bore andthe remainder of said surface being substantially Within the curve ofthe path of revolution of said first named portion.

3. A rotarycutter having a single cutting edge transverse to itsperiphery and a peripheral surface a portion ofwhich' beginning at saidcutting edge is'formed on a curve that gradually approaches the axis ofrotation of the cutter for substantially half the distance around thecutter, the remainder of said peripheral surface being substantiallyWithin the curve of the path of revolution of said first named portion;

4. A rotary cutter formed as a single piece having a recess in itsperiphery to provide a cutting edge and a peripheral surface extendingaround the cutter from said cutting edge to the opposite side of saidrecess, said piece being provided With a'bore to permit the cutter to bemounted upon its operating shaft, said bore being located farther "fromripheral portion of the cutter.

. 5. A rotary cutter having a smgle cutting edge transverse to itsperiphery, the cutter having a portion of its peripheral surface ofrevolution beginning at said cutting edge formed on a curve thatgradually approaches the axis of rotation ofthe cutter and the remainderof its peripheral surface formed on a curve described about an axisnon-coincident With the axis of the curve of said first named portion. Ia

6. A rotary cutterformed With a single cutting edge transverse to itsperiphery, the cutter having a portion of its peripheral surface ofrevolution beginning at said cutting edge. formed on an are describedabout an axis at one side of the axis ofrotation of the cutter, and theremainder of said surface formed on an arc described about an axissubstantially coincident With said axis of rotation.

7. A rotary cutter of greater diameter at one end than at the other andhaving a single cutting edge transverse to its periphery, thecutterhaving a portion of its peripheral surface of revolution beginning atsaid cut-' ting edge formed on a curve that gradually approachesthe'axis of rotation of the cutter and described about an axisnon-parallel to said axis of rotation and the remainder of said surfaceformed on a curve described about an axis substantially coincident withsaid axis of rotation.

8. Arotary cutter of greater diameter at one end than at the other andhaving a cutting edge and a peripheral surface extending from said edgeon a curve that gradually approaches the axis of rotation of the cutterforsubstantially half the distance around the cutter, said cutter beingformed also to provide lateral clearance behind the cutting edgeincreasing for substantially half the distance around the cutter.

9. A rotary cutter of-greater diameter at one end than at the other andhaving a single cutting edge transverse to its periphery, the cutterbeing formed to provide both radial and lateral clearance for aportionof-the distance around the cutter and to provide radial clearance: forthe remainder of the distancearound the cutter.

10. A rotary cutter having a single cutting edge transverse to itsperiphery and a=peripheral surface of revolution beginning at saidcutting edge described about an axis non-parallel to the axis ofrotation of the .of revolution beginning at said cutting edge describedabout an axis which is non-parallel to the axis of rotation of thecutter and diverges from said axis of rotation in the direction of thelarger end of the cutter.

12. A rotary cutter of greater diameter at one end than at the other andhaving a peripheral surface concavely curved in transverse contour witha single cutting edge extending across the periphery, said cutter havinga peripheral surface of revolution beginning at said cutting edgedescribed about an axis that is nearer to said cutting edge than theaxis of rotation of the cutter and diverges from said axis of rotationin the direction of the larger end of the cutter.

13. A rotary cutter having a single cutting edge transverse to itsperiphery and a pcripheral surface of revolution beginning at saidcutting edge described about an axis that extends across the cutter, thecutter having a bore the axis of which is nonparallel to the axis aboutwhich said surface is described.

14. A rotary cutter of greater diameter at one end than at the other andhaving a cutting edge transverse to its periphery and a peripheralsurface of revolution beginning at said cutting edge described about anaxis that extends across the cutter, the cutter having a bore sodisposed relatively to said cutting edge and to the axis about whichsaid surface is described as to provide both radial and lateralclearance behind the cutting edge. j

15. The method of making rotary cutters which consists in forming ablank of greater diameter at one end than at the other with a singlecutting edge transverse to its periphery, and forming a bore in theblank in such relation to the periphery of the blank as to provide bothradial and lateral clearance. behind the cutting edge when the cutter isrotated about the axis of said bore.

16. The method of making rotary cutters which consists in forming asubstantially circular blank of greater diameter at one end than at theother, making a slot in the blank to provide a cutting edge transverseto the periphery of the blank, and forming a bore in the blank in suchrelation to the cutting edge and to the axis of the blank as to provideboth radial and lateral clear ance behind the cutting edge when thecutteris rotated about the axis of said bore.

117. The method of making rotary cutters which consists in forming ablank of greater diameter at one end than at the other with a singlecutting edge transverse to its periphery, and forming a bore in theblank relatively remotefrom said cutting edge with the axis of the boreso inclined relatively to the axis of the blank as to provide lateralclearance for that portion of the peripheral surface near the larger endof the cutter when the cutter is rotated about the axis of said boreneeaeea 18. The method of making rotary cutters which consists informing a blank of greater diameter at one end than at the other with asingle cutting edge transverse to its periphery, forming a bore in theblank in such relation to the periphery of the blankas to provide bothradial and lateral clearance behind the cutti-ig edge when the cutter isrotated about the axis of said bore, and forming an end face of thecutter in perpendicular relation to the axis of said bore.

19. The method of making rotary cutters which consists in forming asubstantially circular blank of greater diameter at one end than at theother with .a single cutting edge transverse to its periphery, forming abore in the blank with its axis in non-parallel relation to the axis ofthe blank to provide lateral clearance behind the cutting edge when thecutter is rotated about the axis of said bore, and forming an end faceof the blank in perpendicular relation to the axis of said bore.

20. The method of making rotary cutters which consists in forming asubstantially circular blank of greater diameter at one end than at theother, making a slot in the blank to provide a cutting edge transverseto the periphery of the blank, forming a bore in the blank with its axisin non-parallel relation to the axis of the blank to provide lateralclearance behind the cutting edge when the cutter of said bore, andforming the end faces of the blank is perpendicular relation to the axisof said bore.

21'. The method of making rotary cutters which consists in forming asubstantially circular blank, making a slot in the blank to provide acutting edge transverse to its periphery, and forming a bore in theblank in such relation to the periphery as to provide radial clearancebehind the cutting edge when the cutter is rotated about the axis ofsaid bore.

22. The methodv of making rotary cutters which consists in fonning asubstantially circular blank, making a slot in the blank to provide atthe rear of the slot a cutting edge transverse to the periphery of theblank, forming a bore in the blank relatively near to that portion ofthe blank which is diametrically oppositeto said cutting edge, andcutting away a portion of the blank at the periphery between saiddiametrically opposite portion and the front of said slot.

23. The method of making rotary cutters which consists in forming asubstantially circular blank of greater diameter at one end than at theother, making a slot in the blank to provide at the rear of the slot acutting edge transverse to the periphery of the blank, forming a bore inthe blank relatively near to that portion of the blank which is diam icly opposite to said out:

is rotated about the axis ting edge with the axis of the bore at anangle to the axis of the blank to provide lateral clearance behind thecutting edge when the cutter is rotated about the axis of said bore,forming the end faces of the blank in perpendicular relation to the axisof said bore, and cutting away a portion at the periphery of the blankbetween said diametrically opposite portion and the front of said slot.1)

In testimony whereof I have signed my name to this specification. v

HENRY LOOMER.

Copies of this patent maybe obtained for five cents each, by addressingthe commissioner of Patents,

. Washington, D. G.

